Ab initio quantum-chemical computations of the electronic states in HgBr2 and IBr: Molecules of interest on the Earth’s atmosphere

J.Z. DAVALOS; D.R. ALCOBA; S.P. SITKIEWICZ; NOTARIO, RAFAEL; O.B. OÑA; J.M. OLIVA; A. SAIZ-LOPEZ; D. ROCA-SANJUAN; J.Z. DAVALOS; D.R. ALCOBA; S.P. SITKIEWICZ; NOTARIO, RAFAEL; O.B. OÑA; J.M. OLIVA; A. SAIZ-LOPEZ; D. ROCA-SANJUAN

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Año: 2016 vol. 145 p. 244304 - 244304

0021-9606

The electronic states of atmospheric relevant molecules IBr and HgBr2 are reported, within the UV-Vis spectrum range (170nm Ephoton 600 nm) by means of the complete-active-space self-consistent field/multi-state complete-active-space second-order perturbation theory/spin-orbit restricted-active-space state-interaction (CASSCF/MS-CASPT2/SO-RASSI) quantum-chemical approach and atomic-natural-orbital relativistic-correlation-consistent (ANO-RCC) basis sets. Several analyses of the methodology were carried out in order to reach converged results and therefore to establish a highly accurate level of theory. Good agreement is found with the experimental data with errors not higher than around 0.1 eV. The presented analyses shall allow upcoming studies aimed to accurately determine the absorption cross sections of interhalogen molecules and compounds with Hg that are relevant to better comprehend the photochemical processes taking place in the atmosphere.